1. Field of the Invention
The present invention relates to an air flow adjusting rear member of a helmet.
2. Description of Related Art
When driving a motorcycle at high speed while wearing a helmet, a strong wind pressure acts on the front part of the helmet on the head of a cyclist. The wind passing by the helmet results in negative pressure (turbulence) at the lower back of the helmet and this negative pressure pulls the helmet backward, thereby creating a great stress to the cyclist's neck muscles.
Conventional art provides an air flow adjusting rear member (inverted visor) fixed to the rear portion of a helmet (see U.S. Pat. No. 4,586,197).
This air flow adjusting rear member is designed to be completely fixed with rivets, screws, or adhesive materials.
In other words, the conventional air flow adjusting rear member is fixed to the lower back rim to extend upwardly and rearwardly therefrom and covers the lower back portion of the helmet, thereby allowing maximum relaxing of neck muscles at each speed, depending upon speed of a motorcycle and tilt of the head of a wearer.
Such conventional air flow adjusting rear member is fixed to the helmet and thus cannot be removed when necessary. For example, the air flow adjusting rear member must be removed in at least the following cases: when the air flow adjusting rear member is broken and needs to be replaced with a new one; when a user (rider) wants to replace an air flow adjusting rear member with another having a different color, shape, or size; and when a user wants to use a helmet without an air flow adjusting rear member.
Since the air flow adjusting rear member is fixed and cannot be removed from a helmet, the whole helmet must be abandoned if only the air flow adjusting rear member is damaged even though the body of the helmet is left unbroken. Additionally, a mounting site of the air flow adjusting rear member cannot be adjusted to account for various conditions such as a posture of a rider, an average range of traveling speeds, the direction of the wind, and wind pressure.
In another aspect, when rivets or screws are used to fix the air flow adjusting rear member to a helmet, the body of the helmet is holed, so it is necessary to increase a strength of the helmet in consideration of the holes, thereby increasing the cost of the helmet.
It can be considered to form the air flow adjusting rear member integrally with a helmet at an initial stage. However, this has a problem of requiring many variants of helmets and disadvantages in manufacturing cost or distribution. For users, they may need to purchase both general helmet and helmet with an air flow adjusting function, thereby having a burden economically or practically.